It is often desirable to electrically interconnect contact terminals in an electrical connector assembly to circuits on a circuit board or panel by means other than solder. One such means is the use of compliant pin terminals such as those disclosed in U. S. Pat. No. 4,186,982. Insertion of such terminals into a circuit board, however, requires the application of a sufficient amount of axial force to overcome the normal force between the split sections of the compliant pin and a plated through-hole thereby allowing the compliant pin portions to move through the plated through hole and establish electrical contact. Typically each compliant pin terminal requires approximately forty pounds of axial force to insert the terminal into the circuit board. Owing to the high insertion force, compliant pin terminals have generally been limited to square post terminals that are sufficiently strong to withstand the level of force required to insert the terminal into the board.
In some applications, however, it is desirable that the electrical terminals in the electrical connector assemblies include compliant pin portions having contact portions with a more complex structure than square posts. The configuration of such contact members may be quite varied, but generally they are stamped and formed members of relatively light gauge metal. As such, the contact portions or members members are not adapted to be engaged by insertion tools nor capable of sustaining substantial levels of force required for insertion thereof into their respective housings or into circuit boards where insertion would encounter substantial resistance.
For purposes of illustrating the invention, the contact portion is shown as a serpentine type contact member. It is to be understood, however, that the contact portion is not limited to the serpentine structure and that the profile of the contact portion may have many different shapes. Serpentine type contacts or terminals in electrical connectors are well known in the art, as represented by U.S. Letters Pat. No. 3,208,030. These serpentine contacts comprise a relatively-thin flexible strip of metal, at least a portion of which may be plated, which is folded back upon itself several times to form a continuous "bellows" or "serpent" contact. The serpentine contact has an end portion thereof formed as a spring finger or latch that cooperates with an internal ledge formed within an insulated connector housing member that houses the serpentine contact; and the spring latch may be manually depressed, using a suitable tool, in order to remove the serpentine contact from its insulated housing member. The serpentine contact as disclosed in the above patent is generally used with solder connections or for crimping to wire members. Additionally, these serpentine contacts are hermaphroditic, so that a plurality of serpentine contacts in a first connector may matingly engage a corresponding plurality of similar serpentine contacts carried by a complementary second connector.
For some applications, it is desirable that the serpentine contacts be securable to a compliant pin terminal (or compliant pin terminal post) which is an elongated terminal adapted to be received with an interference fit (for example) within a plated opening formed in a circuit board; and the circuit board, for example, may constitute a backplane of a computer apparatus. When the serpentine contact is carried by the compliant pin terminal, the serpentine contact interferes with a direct engagement of the compliant pin terminal by an insertion tool such as a push rod (or other tool) carried by a ram-type of press.
The prior art is further represented by U.S. Letters Pat. No. 4,553,322, wherein the push pins carried by the ram tool enter terminal-containing passageways of a connector and extend through socket portions of the terminals to engage push surfaces of the respective terminals, pushing the terminal post portions into respective holes of a circuit board.